The bus trip will limit you a bit. There are a few websites that I would suggest (both for quilt shopping and for sight seeing):
http://www.quiltart.com/lancaster.html
http://www.padutchcountry.com/shoppi...ter-quilts.asp
If you get a chance to see ZOOK's it is a good store to shop in (I've not been there in 6 years so remember this might be dated information). It is in a town called (okay smile now) Intercourse PA. It is in Lancaster County and in a very rich shopping area that many tour buses go to (lets say a destination).
In the town of Gettysburg there used to be a quilting store - which specialized in Civil War Fabrics (I know that may be a bit obvious). I'm not sure if it is still there but you may want to look for it online!
You should have a GREAT visit! Take pictures and update us!!!
Weather - it is April so you will want to layer!